Modern consumer multimedia devices (such as portable media players, personal navigation devices, mobile internet device etc) typically have the capability to provide (high quality) video output, e.g. at a display of the device. However, limitations of camera sensors, video compression, transmission of the video through communication channels adversely affect the video quality due to unwanted effects.
Flickering is an example of such an unwanted effect. It can occur in television systems and the like that use an interlaced scan line technique in order to minimize the signal bandwidth used. With the interlaced scan line technique, an image is displayed as two scan line fields; one scan line field comprising the odd horizontal lines of the image; and the second scan line field comprising the even horizontal lines of the image. In this manner, odd and even scan line fields of images are alternately displayed, for example at a rate of 60 fields per second for NTSC (National Television System Committee) systems and at a rate of 50 fields per second for PAL (Phase Alternating Line) systems. The alternating of the display of odd and even lines can result in flickering of the image. Flickering can be seen as an aliasing phenomenon, and is the effect caused when high frequency image energy aliases to low frequency image energy, thereby resulting in low frequency flicker where high spatial vertical frequencies are present.
Other unwanted effects can include noise, contrast degradation blur, ringing and the like.